Let's be honest -- geysers are really cool. You've got an eruption of water and vapor that can burst to heights of 185 feet. What's not to like about that?

When building propellant tanks for the world's most powerful rocket, NASA engineers want to make sure Old Faithful stays in Yellowstone. So beginning Aug. 5, anti-geyser testing is underway at NASA's Marshall Space Flight Center in Huntsville, Alabama, for the agency's Space Launch System (SLS) -- the rocket that will make deep space missions possible, including to an asteroid and ultimately to Mars.

A special piece of hardware called a low-profile diffuser is being designed, built and tested at NASA's Marshall Space Flight Center in Huntsville, Alabama, for propellant tanks. The diffuser maintains the density and required flow rate of the propellant. Using a smaller diffuser can free up space to raise the liquid level -- potentially increasing the amount of payload that can be carried on future launch vehicles, like NASA's Space Launch System, or SLS